To read user input you can try the cmd module for easily creating a mini-command line interpreter (with help texts and autocompletion) and raw_input (input for Python 3+) for reading a line of text from the user.
text = raw_input("prompt") # Python 2
text = input("prompt") # Python 3
Command-line inputs are in sys.argv. Try this in your script:
There are two modules for parsing command-line options: (deprecated since Python 2.7, use argparse instead) and get opt. If you just want to input files to your script, behold the power of file input